Author: Owen Pan Date: 2024-02-20T00:28:26-08:00 New Revision: 119a72866f0e143127355fe6e03f57c4f8bab1ae
URL: https://github.com/llvm/llvm-project/commit/119a72866f0e143127355fe6e03f57c4f8bab1ae DIFF: https://github.com/llvm/llvm-project/commit/119a72866f0e143127355fe6e03f57c4f8bab1ae.diff LOG: [clang-format][NFC] Remove redundant calls to guessIsObjC() Running clang-format on the following input ``` int lambdas() { return [&] { return [&] { return [&] { return [&] { return [&] { return [&] { return [&] { return 3; } (); } (); } (); } (); } (); } (); } (); } ``` will finish instantly if you pass clang-format a .cpp input with this content, but hang for tens of seconds if you pass the same via stdin or a .h file. Adding some debug statements showed that guessIsObjC was getting called tens of millions of times in a manner that scales very rapidly with the amount of nesting (if clang-format just takes a few seconds with that input passed on stdin, try adding a couple more levels of nesting). This change moves the recursive guessIsObjC call one level of nesting out of an inner loop whose iterations don't affect the input to the recursive call. This resolves the performance issue. Authored-by: davidvc1 and Uran198 Differential Revision: https://reviews.llvm.org/D114837 Differential Revision: https://reviews.llvm.org/D47515 Added: Modified: clang/lib/Format/Format.cpp Removed: ################################################################################ diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp index e67b2101f5821b..2c815128b1a59d 100644 --- a/clang/lib/Format/Format.cpp +++ b/clang/lib/Format/Format.cpp @@ -2948,9 +2948,9 @@ class ObjCHeaderStyleGuesser : public TokenAnalyzer { << getTokenTypeName(FormatTok->getType()) << "\n"); return true; } - if (guessIsObjC(SourceManager, Line->Children, Keywords)) - return true; } + if (guessIsObjC(SourceManager, Line->Children, Keywords)) + return true; } return false; } _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
